Documentation sections

Magnetic Flux Density Converter

POSThttps://rftools.io/api/py/v1/calculate

Slug magnetic-flux-units. Convert magnetic flux density between Tesla, milliTesla, microTesla, Gauss, and nanoTesla for sensor and motor applications.

Inputs

Send every one of these in inputs, in the units shown. Most are required: a call without one is refused (400) and costs nothing; one the calculator can do without takes the default shown. An input outside its range is still computed and flagged in the provenance.

Inputs of magnetic-flux-units
Name	Unit	Range	Default	Description
teslanumber	T	at least 0	0.001	Magnetic Flux Density

Outputs

Returned in values, by key. A value that is unbounded or undefined is null.

Outputs of magnetic-flux-units
Field	Unit	Description
milliteslaheadline	mT	Millitesla
microtesla	μT	Microtesla
nanotesla	nT	Nanotesla
gauss	G	Gauss

Calling it

Calculate: one call, the request and response in full, and its errors.
Batch: this calculator with others, or a sweep, in one request.
Solve for a target: the value of one input that brings an output to a target.

curl -X POST https://rftools.io/api/py/v1/calculate \
  -H "X-API-Key: $RFTOOLS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "slug": "magnetic-flux-units",
    "inputs": {
      "tesla": 0.001
    }
  }'

import rftools

client = rftools.Client()  # reads RFTOOLS_API_KEY, or the key `rftools login` saved

result = client.calculate("magnetic-flux-units", {"tesla": 0.001})
print(result.values)
print(result.warnings, result.provenance.formula_ref)

const response = await fetch("https://rftools.io/api/py/v1/calculate", {
  method: "POST",
  headers: {
    "X-API-Key": process.env.RFTOOLS_API_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "slug": "magnetic-flux-units",
    "inputs": {
      "tesla": 0.001
    }
  }),
});
console.log(response.status, await response.json());

package main

import (
	"bytes"
	"fmt"
	"io"
	"net/http"
	"os"
)

func main() {
	body := []byte(`{
	  "slug": "magnetic-flux-units",
	  "inputs": {
	    "tesla": 0.001
	  }
	}`)
	req, err := http.NewRequest("POST", "https://rftools.io/api/py/v1/calculate", bytes.NewReader(body))
	if err != nil {
		panic(err)
	}
	req.Header.Set("X-API-Key", os.Getenv("RFTOOLS_API_KEY"))
	req.Header.Set("Content-Type", "application/json")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	out, _ := io.ReadAll(res.Body)
	fmt.Println(res.Status, string(out))
}

application/json

{
  "slug": "magnetic-flux-units",
  "values": {
    "millitesla": 1,
    "microtesla": 1000,
    "nanotesla": 1000000,
    "gauss": 10
  },
  "warnings": [],
  "errors": [],
  "provenance": {
    "method": "calculator:magnetic-flux-units",
    "version": "api@3f2c1a9b04de",
    "formulaRef": null,
    "assumptions": [],
    "validRange": {
      "status": "inside",
      "bounds": {
        "tesla": {
          "min": 0,
          "max": null,
          "unit": "T"
        }
      },
      "outside": [],
      "model": null
    },
    "computedAt": "2026-09-24T14:05:11.003Z",
    "inputs": {
      "tesla": 0.001
    },
    "seed": null,
    "elapsedSeconds": 0.003
  }
}

{
  "detail": [
    {
      "type": "float_parsing",
      "loc": [
        "body",
        "inputs",
        "tesla"
      ],
      "msg": "Input should be a valid number, unable to parse string as a number",
      "input": "abc"
    }
  ]
}

An input sent as text. Nothing was counted.

{
  "detail": "More than 120 requests in 60 seconds from this address.",
  "errorKind": "rate_limited",
  "limit": 120,
  "windowSeconds": 60,
  "upgradeUrl": "https://rftools.io/pricing/"
}

Too many requests in a minute, with Retry-After.

Same inputs on the calculator pageMagnetic Flux Density Converter, at these values